1. Field of Art
The present invention relates to a device for fixing a wire harness which is installed in an automobile or the like, in such a manner that the wire harness can be bent smoothly in a three dimensional direction thereby to be prevented from being damaged.
2. Description of the Related Art
FIG. 5 shows an example of a conventional device for fixing a wire harness.
A device 76 for fixing a wire harness is intended to fix the wire harness 73 to a vehicle body or the like. The wire harness 73 is composed of a plurality of electric wires 72 covered with a corrugate tube 71. The corrugate tube 71 is made of synthetic resin and formed into a thin-walled cylindrical shape. The corrugate tube 71 is rich in flexibility, having circumferential grooves and ridges which are alternately arranged at an equal pitch in parallel in a longitudinal direction of the tube.
The corrugate tube 71 serves as an electric wire protecting tube, and can be easily curved together with the plurality of the electric wires 72 in correspondence with a curved shape in two or three dimensions of a panel 75 of the vehicle body or the like which is a site 74 to be mounted, so that workability in installing the wire harness 73 can be enhanced.
There have been two types of the corrugate tube 71, as to whether or not the corrugate tube is provided with a slit in a longitudinal direction. In the corrugate tube 71 of the type having the slit, the electric wire 72 can be easily inserted into the corrugate tube 71 through the slit. On the other hand, in the corrugate tube 71 of the type having no slit, an insertion work of the electric wire 72 is rather annoying, but there is no anxiety that the slit may be opened, and so, it is not necessary to wrap a vinyl tape around the corrugate tube 71 for preventing the slit from being opened.
The device 76 for fixing the wire harness is designed, for example, as a clamp for pressing the corrugate tube 71 onto the panel 75 at the mounted site 74. The device 76 for fixing the wire harness has to be necessarily arranged along at least the curved areas of the mounted site 74 such as the vehicle body or the like. It is also possible to employ other fastening means such as a band, as the device for fixing the wire harness.
The device 76 for fixing the wire harness is fixed to the panel 75 at the mounted site 74 by means of flexible retaining clips, small screws and so on. The retaining clip (not shown) has a pair of flexible retaining pieces, and adapted to be inserted into a hole in the panel 75 to retain the device 76. In case of using the small screw (not shown), the small screw which is inserted into a bracket of the device 76 is screwed into a threaded hole in the panel 75 to fix the device 76 for fixing the wire harness.
The wire harness 73 is installed along the curved face of the mounted site 74 of the vehicle body or the like, and the corrugate tube 71 surrounding the wire harness is firmly fixed to the mounted site 74, employing a plurality of the devices 76 for fixing the wire harness arranged in a longitudinal direction. In this manner, the wire harness 73 is rigidly fixed to the mounted site 74, and prevented from displacement caused by vibration during a drive of the vehicle, interference of the wire harness 73 with the vehicle body (the mounted site 74), strange noises occurring therefrom, and so on.
The electric wires 72 inside the corrugate tube 71 are protected from rain water, dust and so on by the corrugate tube 71, and at the same time, extended along the vehicle body (the mounted site 74) up to predetermined positions such as an instrument panel, a floor, doors (hinged doors or sliding doors), etc. to be connected to their electric components or auxiliary parts by way of connectors.
However, the above described conventional device 76 for fixing the wire harness has had such a drawback that when the corrugate tube 71 has been fixed with the devices 76 to the curved areas of the mounted site 74 in a cubical shape, such as the vehicle body, in order to fix the wire harness 73, the electric wires 72 as well as the corrugate tube 71 maybe crooked, and torsion may occur. As the corrugate tube itself has received a stress of this torsion, such problems has arisen that the corrugate tube 71 may be deformed or damaged, or the slit may be opened. When the slit has been opened, it has been concerned that the electric wires inside the corrugate tube 71 may be exposed to the exterior and stamped with a foot or the like, and water or dust may intrude from the open slit.
Moreover, there has been such an anxiety that the corrugate tube 71 may be worn or broken from rubbing against an end portion of the device 76 for fixing the wire harness due to a tensional force it has been receiving. Further, in case where the wire harness 73 has been installed at an acute angle, or violently swayed around the device 76 as a fulcrum, the wire harness 73 as well as the corrugate tube 71 has been liable to be deformed or rubbed against the end portion of the device 76 for fixing the wire harness, that is, at the opening from which the corrugate tube 71 has been guided out. In such cases, it has been a problem that the corrugate tube 71 and the electric wires 72 contained therein may be liable to be damaged.
Particularly, when the wire harness is installed along the vehicle body, for example, in a three dimensional shape, the wire harness tends to be bent or swayed vertically and laterally in all the directions. Therefore, it has been eagerly desired that the wire harness may be smoothly curved or swayed in correspondence with the shape, thereby to reliably prevent the wire harness from being worn or damaged due to its torsion or rub.
Although the corrugate tube has been referred to as the protective tube in the above described example of the prior art, such problems as described above are also liable to occur, even in case where other protective means beside the corrugate tube such a net-like tube made of synthetic resin, a soft covering material, or a vinyl tape have been employed.
In view of the above described problems, it is an object of the present invention to provide a device for fixing a wire harness which can reliably avoid a torsion of the wire harness, including a protective tube and electric wires, even though the wire harness has been bent or swayed in a three dimensional direction while the wire harness is being fixed or bent for installation, and can reliably prevent the protective tube and the electric wires from being rubbed or broken.
In order to attain the above described object, there is provided according to the present invention, a device for fixing a wire harness comprising a rotary member which holds the wire harness and has an arc-shaped face in a three dimensional direction on its outer peripheral face, and a body of the fixing device in which the rotary member is held so as to rotate in a three dimensional direction.
Owing to the above described structure, the rotary member holding the wire harness can rotate in a three dimensional direction inside the body of the fixing device, when the wire harness is being installed, bent or swayed. Thus, the wire harness will be smoothly bent in any direction in three dimensions. Moreover, torsion of the wire harness can be effectively absorbed, because the rotary member can rotate in all the directions. In this manner, an excessive bending force or torsional force will not affect the wire harness, and the wire harness will be reliably prevented from being deformed or damaged.
According to another aspect of the invention, in the device for fixing a wire harness, the rotary member has a spherical shape.
Owing to such structure, the rotary movement of the rotary member in the three dimensional direction will be smoothly performed with a constant force, and absorption of the bending force and torsional force by the rotation of the rotary member can be more smoothly performed.
According to a further aspect of the invention, in the device for fixing a wire harness, the rotary member can be divided into pieces.
This structure will facilitate attaching and detaching operations of the wire harness to the rotary member, and enhance assembling workability of the device for fixing the wire harness.
According to a still further aspect of the invention, in the device for fixing a wire harness, the rotary member has an insertion part in which a corrugate tube covering the wire harness is held.
This structure enables the corrugate tube to be held by the rotary member, and the electric wires inside the corrugate tube will be able to move freely. Consequently, a large bending force or torsional force will not be exerted on the electric wires.
According to a still further aspect of the invention, in the device for fixing a wire harness, the rotary member is held in the body of the fixing device so as to move in a longitudinal direction of the wire harness.
On occasion where a tensile force or compressive force is applied to the wire harness when the wire harness is being installed, bent or swayed, the wire harness will move back and forth in a longitudinal direction together with the rotary member, thereby to absorb the tensile force and compressive force. Moreover, because the wire harness is projected long to the exterior of the body of the fixing device as the rotary member advances, the wire harness will be able to be curved with a large radius, and thus, the wire harness will be prevented from being affected by an excessive bending stress and from interfering with the exterior. Consequently, deformation, abrasion, or damages of the wire harness will be avoided.
According to a still further aspect of the invention, in the device for fixing a wire harness, the body of the fixing device has a space having a uniform inner diameter for receiving the rotary member, and stopper parts against which the rotary member is abutted at opposite ends of the space in its axial direction.
This structure enables the rotary member to slide freely and smoothly in the axial direction along the space in the body of the fixing device, thereby to smoothly absorb the tensile force or compressive force in the axial direction of the wire harness, and the wire harness will be able to be curved with a large radius. The most advanced position and the most retreated position of the rotary member are determined by abutment of the rotary member against the stopper parts.
According to a still further aspect of the invention, in the device for fixing a wire harness, the stopper parts have smooth guide faces in correspondence with an outer peripheral face of the rotary member.
Owing to the structure, in a state where the rotary member is abutted against either of the stopper parts, the rotary member can rotate in a three dimensional direction with a small force without cogging. Thus, the wire harness will be able to be more smoothly curved with a large radius.
According to a still further aspect of the invention, in the device for fixing a wire harness, either one of the body of the fixing device and the rotary member is provided with a harness guide wall in a curved shape.
Owing to this structure, the wire harness guided out from the rotary member is curved with a large radius along the harness guide wall. As the results, the wire harness will be smoothly curved and prevented from being damaged. Moreover, with the back and forth movement of the rotary member in a longitudinal direction of the wire harness, the wire harness will be contacted with the harness guide wall at different contact positions, and contact load will be dispersed. Consequently, abrasion of the wire harness can be decreased.
According to a still further aspect of the invention, in the device for fixing a wire harness, the harness guide wall has a longer wall portion which comes in contact with the wire harness when the rotary member has advanced, and a shorter wall portion which comes in contact with the wire harness when the rotary member has retreated.
Owing to the above described structure, a distance from the rotary member to a distal end of the harness guide wall will be substantially the same in both the advanced position and the retreated position of the rotary member, and the wire harness can be held with the substantially same radius of curvature by means of the longer wall portion and the shorter wall portion of the harness guide wall. Thus, the wire harness will be free from an excessive bending force, smoothly curved with a large radius, and prevented from being damaged.
According to a still further aspect of the invention, in the device for fixing a wire harness, the body of the fixing device can be divided.
This structure facilitates attaching and detaching operations of the rotary member and the wire harness to the body of the fixing device, and assembling workability will be enhanced.
According to a still further aspect of the invention, in the device for fixing a wire harness, the body of the fixing device is a part of a harness protector.
Owing to this structure, the wire harness will be safely protected in the harness protector without interfering with the exterior.
In conclusion, according to the present invention, quality of the wire harness will not be deteriorated with time, and reliability of the wire harness in power supply and signal supply will be enhanced.